I had the 16 zone Rachio but due to upgrading my zones, needed to get an 18zone controller. My dealer recommended the hydrawise. I switched and hate it. I want to go back to rachio but need to figure out how to combine 2 units. A few questions:

Do they need to be separate accounts?

Can it all be programmed as one unit or as if 2 separate units?

I know there is no support for this but please hel me get back to Rachio.

@nehsmit - When you say water sensor I’m assuming that you’re referring to a rain sensor. I wouldn’t connect the rain sensor to both units as they could be on different phases. I’d put the rain sensor on the 16 zone unit and let the weather intelligence handle the two zones on the second controller. If you needed or wanted a rain sensor on the second unit, I would either use a relay to provide the signalling off the current rain sensor or buy a second rain sensor.